Where I live in Maryland is on the outskirts of DC, and my backyard literally IS Rock Creek Park. I'd guess we're roughly neighbors and whatever you have, I have in greater quantity. Lived here for 40+ years, this time of year especially, our yard and outside of house is loaded with spiders of all shapes and sizes. Never had an incident, although at least once a week I find one inside the house. Never the kind I see in webs outside, though - I catch 'em and look 'em up on the internet all the time - from the info you've provided, and my own experience, the one's you're seeing are likely of 2 varieties. The 1st one is big and ugly, but they are bug eaters and very shy people. Usually sense you coming and GTFO of the way before you run into the web, they're pretty savvy like that. Called 'Garden Spiders' generically, they are some sort of variation of Orb Weaver. They are harmless. When we walk around outside the house this time of year, especially in low-light conditions, we wave our arms up and down in front of us as we walk. Never had an issue.
Second kind much smaller and looks more like it could be problematic - big abdomen, thin legs, spins a very chaotic web as opposed to a picturesque, orderly one. They just LOOK like they might be trouble. Nothing further from the troof. These are harmless as well, and actually beneficial. Rarely, if ever see them INSIDE, inside (they hang out a lot in the corners of doorways and all over our porches, overhangs, roofs, windows, etc...you actually want these guys around because they hunt, kill and eat the ones that actually can do you and your family harm (brown recluses and black widows). So if they're around your doors and windows, they're usually keeping things out of your house that you don't want inside.
The one's you see in houses are mostly generically called 'house spiders' and will come in this time of year. Dime size, maybe a little bigger sometimes. Usually black, with some red and gray on 'em sometimes - they catch rides in on pets most of the time. You might get a bite every once in a blue moon, but for the most part, you can just scoop 'em up and put 'em back outside.
Grass spiders look like miniature wolf spiders on a diet. Pretty much harmless, too, although these are the ones I find running on me now and then, and that kind of gives me the willies. Very, very shy. They can bite, but rarely do. They do a lot of running and hiding from things bigger than them, although they are pretty aggressive killers of things their own size or smaller.
I rarely if ever kill 'em. Grandparents and parents (Hungarian/Ukranian heritage) raised me to believe they were good luck, and bad luck if you killed 'em. I need all the luck I can get.
HTH?